I have been reading a lot on the site about Vortec Heads. I have a set of Fast Burn Cylinder Heads I am putting on a 383 GMPP Short Block. Firstly, I am in the process of selecting a Camshaft. The engine is going in a 4x4 with a 4 speed transmission. Any recommendations? My other question is about the maximum lift that these heads will utilize without having to do any machine work to them. I have read that Vortec heads can only go to .450 without having the valve guides cut down. Is that the same with the FastBurn Heads? I have already had the springs changed to a set for a Crane Hydraulic Roller with over .500 lift. The reason I am not using this camshaft is it was bought originally to go with the FastBurn Heads on a 1969 302 with a single plane Intake Manifold for the FastBurn Heads and now I plan on using a dual plane Intake Manifold to develop more low RPM torque. Thanks

Are you wanting to stay roller? What are the specs on the roller you have?

On the heads, the casting numbers are what is really important. What are the casting numbers. That will tell a lot about how much material can be milled out before you get into the water jacket.

I believe that the fastburns, from the factory, are good to about .520 lift before you run into clearance problems. I would definately check 1st though.

Fastburn's are good to 0.525" lift on intake and exhaust.

If you are using a GMPP block that can accept GM roller lifters, and your cam specs are under 0.525" lift, I would highly recommend staying with the GM springs and parts. They are top quality pieces designed to work with GM roller lifters.

If using aftermarket roller lifters do some hunting in the archives. I've posted some info on how to use standard aftermarket parts to get 0.600 lift with no machining necessary. The aftermarket lifters are heavier than the GM parts.

There's little reason to go more than 0.525" lift on these heads, especially on a torque application. Flow starts to stall and swirl tapers off dramatically after 0.550".

There's a bunch of info at Team Chevelle and on the Sallee Chevrolet websites in their respective archives.

[ 04-11-2004, 02:15 PM: Message edited by: CarlC ]

GMPP recommends no more than .525 valve lift as they come from the General. CarlC has a method for getting more lift with a drop in spring and retainer change - hopefully he'll see this and respond. If not - I have it saved somewhere.

Yes, I want to keep a Hydraulic Roller. Both of the Camshafts I have are in the .600 lift range. Way tooooo big for these heads. As I am basically copying the GMPP 383CI/450HP Engine from Sallee Chevrolet I would like to have a Comp Cams camshaft comparable with the GMPP Hot Cam. GMPP lists the Hot Cam of having a Lift of .525I/.525E and a Duration of 218I/228E. I know they also use 1.6 ratio Rocker Arms with the Hot Cam option so I don't know if the camshaft has a lift of .350 with 1.5 ratio Rocker Arms or .328 with 1.6 ratio Rocker Arms. Therefore, I am looking for a Comps Cam of similar size and characteristics. The reason for the Comp Cam brand choice is they are willing to take the Hydraulic Roller that I have as trade on a different camshaft. But I guess I am limited to .525 lift after reviewing the abover replys to my initial question. So can someone give me a suggestion with part number of a Comp Cams Camshaft that is similar to the GMPP Hot Cam? Thanks.

If you are using the GMPP late model block there is a 4X4 cam, P/N X4270HR that should work nicely. 220/224 @ 0.050, 0.474"/0.474", 111 LSA. Confirm with Comp for compatibility with your block.

Comp can also grind whatever you wish. Just tell them your requirements and they can wittle one up for you.

I'm not sure but I recall reading somewhere about a retro-fit cam gear setup that allows the use of later model (HOT Cam) cams in earlier blocks. You might want to contact Dynagear, Speed Pro, etc. to confirm.

Sallee had some Comp roller rocker arms on clearance a while back. Stainless Magnums, for Fastburn/Vortec with side rail guidance for around $225. It's the deal of the century if they still have them.

Here is a CC hyd roller that is very similar to the hot Cam.

http://www.compcams.com/information/Products/Camshafts/DynoSheets/XR270HR-10_001.asp